Neurons communicate by sending chemical signals called neurotransmitters across synapses, specialized connections between two individual cells. This communication requires a delicate and intricate molecular architecture. A recent paper published in Nature has now shown that the structure of this intercellular space is more complicated than previously thought, and it probably helps boost the efficiency of the signaling.

The authors of this paper imaged three proteins found in the cell that starts the signaling process. (Generically called presynaptic proteins, the ones looked at here are RIM1, RIM2, Munc13, and bassoon). Each of these proteins was specifically tagged, and the authors plotted the density of their distribution across the active zones of the synapse.

The team then developed an algorithm that allowed them to identify small clusters of protein based on their local density. These nanoclusters were more likely to be located near the center of each synapse than near the synaptic edges. This wasn’t true of all the proteins, but at least two were tightly restricted and a third less so (bassoon was almost uniform throughout the synapse).